Structure of the sequences adjacent to the centromeric alphoid satellite DNA array on the human Y chromosome

Eighteen yeast artificial chromosome (YAC) clones containing alphoid satellite DNA and adjacent sequences from the human Y chromosome have been identified from three different YAC libraries. Restriction site mapping of the genomic alphoid arrays and the YACs has allowed seven of the alphoid clones to be positioned on the arrays. Three clones extend into flanking sequences. At one edge the alphoid DNA is highly diverged and is flanked by a small block of the 48 base-pair satellite, dispersed moderately repeated sequences and a separate short alphoid array. More distal sequences are Y-specific. At the other edge there is much less divergence and the alphoid DNA is flanked by an Alu sequence and the five base-pair satellite.